AP BIOLOGY FINAL STUDY GUIDE UNIT 3

Describe how enzymes work. Make sure to include the terms products, reactants, and activation energy.

-enzymes work by binding to a reactatn and holding them in such a way that the chemical bond-breaking and bond-forming process take place more readily

-reaction coordinate diagram showing the course of a reaction with and without a catalyst

-with the catalyst the activation energy is lower without it

How can a scientist make an enzyme reaction increase in production rates?

increasing enzyme concentration will speed up the reaction, as long as there is a substrate available to bind to

What could slow down the creation of products from an enzymatic reaction? Give at least three items.

-temperature- raising temperature generally speeds up a reaction and lowering a temperature usually slows down a reaction

-pH- each enzyme has an optimum pH range, changing the pH outside of this range will slow down enzyme activity

-enzyme concentration- increasing an enzyme concentration will speed up the reaction, as long as there is a substrate to bind to

What is denaturation? What causes this process to occur?

-process that modifies the molecular structure of a protein

-caused by external stress on the protein, such as solvents, inorganic salts, exposure to acids or bases, and by heat

What's the concentration of a HCl solution that has a pH of 3.5?

0.0003

Compare the first law to the second law of thermodynamics. Give examples of each.

-first law of thermodynamics states that energy cannot be created or destroyed in an isolated system

-second law of thermodynamics states that the entropy of an isolated system always increases

Compare catabolic to anabolic reactions.

-anabolic refers to the process which builds molecules the body needs, it usually requires energy for completion

-catabolism refers to the process that breaks down complex molecules into smaller molecules, it usually releases energy for the organism to use

Look at the picture to the right. Which diagram (A or B) is an anabolic reaction and which one is a catabolic reaction. How can you tell?

-smaller molecules and uses energy - anabolic reaction

-larger molecules and energy is being released - catabolic

Compare an endergonic to an exergonic reaction. Give examples of each.

-exergonic- the reactants are at a higher free energy level than products ex: cellular respiration

-endergonic- the reactants are at a lower free energy level than the products ex: photosynthesis and the the melting of ice into liquid water

Identify what type of reaction (endergonic or exergonic) occurs when the process happens:

The building of ATP:

endergonic

Identify what type of reaction (endergonic or exergonic) occurs when the process happens:

the breaking down of ATP

exergonic

how is ATP made

glycolysis and cellular respiration

light dependent reactions

-what starts the light dependent reaction- light energy

-what is created- two molecules needed for the next stage of photosynthesis (ATP and NADPH)

-where it takes place- in plants the light reaction takes place in the thylakoid membranes of organelles called chloroplasts

light independent reactions

-what starts it-CO2, an enzyme called ribulose bisphosphate carboxylase, adn three molecules of ribore bisphosphate

-What is created- chemical bonds, ATP and NADPH

-where it takes place- in the stroma, outside the thylakoid membrane

what is the overall reaction for PS

6CO2 + 6H20 + light = C6H1206 +6O

what organisms can perform photosynthesis

plants

How did photosynthesis evolve?

the biochemical capacity to use water as the source of electrons in photosynthesis evolved in a common ancestor of extant cyanobacteria, the geological record indicates that this transforming event took place early in Earth's history at least 2450-2321 million years ago

How are Photosystems II and I different? What colors of light do they like to absorb?

-photosystem I- absorbs the longer wavelength of light which is 700 nm

-photosystem II- absorbs the shorter wavelengths of light which is 680 nm

Glycolysis

-starts- one molecule of glucose

-what is created- two pyruvates, four ATP molecules, and two molecules of NADH

-where it takes place- cytoplasm, within the mitochondrion, the citric acid cycle occurs in the mitochondrial matrix, and oxidative metabolism occurs at the internal folded mitochondrial membrane

Krebs Cycle (Citric Acid Cycle)

-starts- acetyl-CoA and combines with a four carbon molecule called OAA

-what is created- citric acid, which has six carbon atoms

-where does it take place- mitochondrial matrix and generates a pool of chemical energy from the oxidation of pyruvate, the end product of glycolysis, pyruvate is transported into the mitochondria and loses carbon dioxide to form acetyl-Coa

Oxidative Phosphorylation (Electron Transport Chain)

-start- with the arrival of 3 NADH, and one FADH

-end- 2 pyruvate, 2 molecules of water, 2 ATP, 2 molecules of NADH, and 2 hydrogen ions, the NADH carries electrons to the oxidative phosphorylation step of cellular respiration

-where does it occur- in the mitochondrial inner membrane of eukaryotic cells or the cytoplasm of prokaryotes

What occurs when oxygen is not present? Describe the difference between alcohol and lactic acid fermentation.

-when oxygen is not present an organism is not able to undergo aerobic respiration and will undergo fermentation

-fermentation does not require oxygen and is anaerobic

-fermentation will replenish NAD+ from the NADH + H+ produced in glycolysis

-alcohol fermentation- occurs in micro-organisms such as yeast and converts glucose to energy, which is released as carbon dioxide

-lactic acid fermentation- occurs in certain bacteria, yeast and muscle cells and converts glucose to energy, its by-product is lactate

Compare an ectotherm to an endotherm. Give examples of each type of organism.

-ectotherms- are organisms that don't possess the ability to generate sufficient heat to keep themselves warm Ex: reptiles and amphibians

-endotherms- possess the ability to generate their own body heat Ex: people

What did the chromatography reveal in the photosynthesis investigation? How were Rf values calculated?

-the pigments that give the leaf its color can be separated and observed to determine the Rf value of each pigment and their function during photosynthesis

-Rf calculated- equal to the distance traveled by the compound divided by the distance traveled by the solvent front

What are some things that can affect the rate of photosynthesis in algae beads?

carbon dioxide concentration

temperature

light intensity

What are some things that can affect the rate of cellular respiration in algae beads?

increase in carbon dioxide concentration

absence of oxygen

hydrogen ions